#include <iostream>
#include<fstream>
using namespace std;
int a,b,d,t;
int main()
{
    ifstream fin("euclid2.in");
    ofstream fout("euclid2.out");
    fin>>a>>b>>t;
    d=1;
    int verif=1;
    for(int j=1;j<=t;++j)
    {
            if(a<=b)
        {
            if(b%a==0){fout<<a;verif=0;}
            for(int i=2;i<=a/2;++i)
            {
                if(a%i==0 && b%i==0)d=i;
            }
            if(verif==1)fout<<d;
        }
        else
        if(a>b)
        {
            if(a%b==0){fout<<b;verif=0;}
            for(int i=2;i<=b/2;++i)
            {
                if(a%i==0 && b%i==0)d=i;
            }
            if(verif==1)fout<<d;
        }
    }
}